varying vec3 normal;

void main(){

  float red;
  float green;
  float blue;

  red = max(dot(vec3(1.0, 0.0, 0.0), normalize(normal)), 0.0);
  green = max(dot(vec3(0.0, -1.0, 0.0), normalize(normal)), 0.0);       
  blue= max(dot(vec3(0.0, 0.0, -1.0), normalize(normal)), 0.0);
  
  gl_FragColor = vec4(red, green, blue, 1.0);
}